Police in Falls Township, Bucks County, say the stabbing death of a man in September is a case of justifiable homicide.

Mathias attacked his 45-year-old girlfriend with a knife, police say. She managed to get the knife away and fatally stab him.

His girlfriend suffered 'significant defensive wounds' to her hands, police said, and had to undergo surgery and physical therapy.

Police say Mathias had been recently been receiving treatment for his mental health issues.

In a statement, Falls Township police said, "This was a very tragic case which, at its conclusion, determined that a very well-respected, peaceful and generous man suffered from a rapid descent into a major mental health problem very late in life which caused the fateful encounter with the victim."